So, when I am making my own battles, I try to move the scenario setting to "random" for weather, I keep getting an error: Close Combat encountered an internal error at address 0xCCCCCCCC and will now exit.

I was able to track this down, and it is an odd problem. It does not happen in the development build of the game, or while debugging, and appears to be related to how the compiler generates the code for the release version. Regardless, I have fixed it and there will be an update in the near future.